Attenuator assembly



Sept. 13, 1949. DQUCETTE 2,481,649

- ATTENUATOR ASSEMBLY Filed April 25, 1945 E T MAY-u ATTORNEY Patented Sept. 13, 1949 ATTENUATOR ASSEMBLY Edmund Doucette, Newark, N. J assignor to The Daven Company, Newark, N. J., a corporation of New Jersey Application April 25, 1945, Serial No. 590,266

2 Claims.

tact-carrying head of an attenuator, and all in their proper position relative to the markings on the dial or panel with which the attenuator is employed.

A further object of the present invention is to provide an attenuator assembly which offers distinct manufacturing advantages in some types of attenuators over similar ones of present manufacture.

' With thes and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing an attenuator assembly of a preferred form embodying the invention, and the features forming the invention will be specifically pointed out in the claims.

In the drawings:

Figure 1 is a side elevation of an attenuator structure from which the enclosing housing and the electrical resistance coils have been removed for the purpose of avoiding confustion in the illustration.

Figure 2 is an end view of the attenuator looking towards the inner or stationary contactcarrying end.

Figure 3 is a detail longitudinal section taken on the line 3-3 of Figure 2.

Figure 4 is a detail plan view of a locking key employed in the structure.

Figure 5 is a fragmentary end view of the movable switch body.

Figure 6 is a fragmentary end view of the inner end of the attenuator with the switch plate removed.

Referring more particularly to the drawings, the improved attenuator comprises the contactcarrying head i which is made of insulating material and carries the inner circular stationary contact 2 and the outer circle of spaced contacts 3. The contacts 3 are arranged in a circle concentric of the inner contact ring 2 and the axis of the contact-carrying plate I.

In the construction of an attenuator, the contacts have connected thereto the electrical resistance coils which are not shown inthe drawings of the present application, since they form no part of the invention and would only have a tendency to obscure the clearness of the drawings. The contact-carrying head I is connected to the detent (not shown) carrying head 4 by a suitable sleeve 5 through which the switch operating shaft 6 extends. The shaft 6 has the usual type of operating knob l removably mounted thereon and held in place by means of a set screw 8 so that as th knob 1 is' turned, the movable switch member 9 will be rotated about its axis for bringing its contact members I ll into engagement with various ones of the spaced stationary contacts 3. The specific switch structure is clearly shown in Patent No. 2,424,745 issued July 29, 1947, but it is to be understood that any suitable type of switch structure may be employed without departing from the spirit of the present invention.

The switch structure 9 includes the contactcarrying body H which carries the movable contact members Ill. The movable contact members ID are held in proper position for yielding move ment by means of spring members l2, all as described in the application above referred to. The carrying body ll of the switch structure 9 has a bearing sleeve I4 extending therethrough which fits about the shaft 6, and an inwardly extending locking lug I5 is formed in the sleeve [4 a short distance inwardly from its outer end, as clearly shown in Figure 3 of the drawings. The locking lug l5 fits into a cut-out portion iii of the outer end of the shaft 6. The lOCkiIlg lug l5, and the inner longitudinal side of the cut-out portion I6, and flat interengaging surfaces I l and I8, respectively prevent rotation of the sleeve, and, consequently, of the switch member 9, independently of rotation of the shaft 6, and which interengaging surfaces also cause rotation of the sleeve with rotation of the shaft to move the switch member 9 about the contact-carrying head i.

The sleeve M has a radially extending opening l9 therein which receives the reduced pin portion 20 of the locking key 2 I. The head 22 of the locking key is semi-circular in shape and rests against the outer surface of the locking lug l5 when the locking key 2| is in looking position. A spring 23 is coiled about the shaft 6 and engages the inner end of the sleeve I 4 for urging the sleeve and the switch member 9 outwardly to apply yielding pressure from the lug l5 against the head 22 of the locking key 2! to bind the locking key in looking position and prevent accidental disconnection of the locln'ng key, switch member 3, and shaft 6. If it is so desired, the spring 23 may be confined in an enlargement 24 of the sleeve 5 so as to provide an inner abutment for one end of the spring. For assembling or disassembling the structure-when the switch member 9 is mounted upon the end of the shaft 6 it is forced inwardly against the tension of the spring 23 sufiiciently to permit the reduced pin portion 20 of the locking key 2| to be slipped into the opening IS with the head 22 resting against the outer side of the lug I5, and then when the inward forcing pressure is relieved from the switch member, the spring 23 will force the switch member 9 outwardly, causing the locking lug 15 to press against the key 2| and securely bind it in looking position. In the case of disassembly when the switch member 9 is forced inwardly against the tension of the spring 23, the locking key will be relieved of pressure thereagainst and may be easily and quickly removed from its connection with the shaft.

By the provision of the flat interengaging surfaces on the locking lug l5 and the shaft 6, the switch member will always be locked in a fixed definite position relative to the contacts on the contact-carrying head I.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they may be widely modified within the invention defined by t e la ms. i

What is claimed is:

1. In an attenuator having a contact-carrying head a switch member movable relative to said head and provided with a shaft-receiving bore, a shaft for operating said switch member, a sleeve in said bore, said shaft extending into said sleeve and provided with a cut-out portion, a positioning lug formed in said sleeve and engaging in said cut-out portion to connect said shaft and switch member in proper operating position, said shaft provided with a transverse key-receiving opening therein, a locking key having an enlarged head portion and a reduced portion for insertion into said transverse opening, said lug positioned inwardly of the end of said sleeve whereby the head of the locking key is confined within the sleeve.

2. In an attenuator having a contact-carrying head, a switch member movable relative to said head and provided with a shaft-receiving bore, a shaft for operating said switch member, a sleeve in said bore, said shaft extending into said sleeve and provided with a cut-out portion a positioning lug formed in said sleeve and engaging in said cut-out portion to connect said shaft and switch member in proper operating position, said shaft provided with a transverse key-receiving opening therein, a locking key having an enlarged head portion and a reduced portion for insertion into said transverse opening, said lug positioned inwardly of the end of said sleeve whereby the head of the locking key is confined within the sleeve, and a spring for urging said lug against the head of said locking key to bind the locking key in looking position.

EDMUND DOUCETTE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 580,459 Mielchen Apr. 13, 1897 ,337,765 McGuckin Apr. 20, 1920 1,998,649 Arden Apr. 23, 1935 2,026,773 Dressel et a1. Jan. '7, 1936 2,091,472 Douglas Aug. 31, 1937 2,185,511 Mazer Jan. 2, 1940 

